Naturalist Notebook: Squirrels, Swimming Eagles, and Shaggy Mice

Question, readers: Where on the Key Peninsula are you seeing eastern gray squirrels? Have you seen them interact with our native Douglas squirrel? How did the interaction go? Any intel would be helpful.

Gray Squirrels Incoming

Eastern gray squirrels were released in western Washington several times in the last century to populate parks and neighborhoods. They are firmly established. (Washington has another gray squirrel with a delightfully bushy tail, the western gray squirrel, but it’s a beast of continuous oak canopy and is restricted to three small areas in Washington.)

As far as ecosystems go, the eastern gray squirrel is adapted to eastern deciduous forests, hence its comfort in the burbs. Ostensibly, there is little habitat overlap or competition between it and our beloved Douglas squirrel, the chickaree, which is a conifer specialist. In most parts of western Washington, you have one or the other.

Nothing is so simple on our lovely little peninsula.

You have suburban next to rural, landscaped next to farmed, and formerly farmed and forested. I’ve seen eastern gray squirrels along cedar- and pine-forested wetlands. I see chickarees taking advantage of bird feeders. The two squirrels are clearly rubbing shoulders in all kinds of habitats.

Eastern gray squirrels do seem to be spreading. Are they everywhere on the peninsula by now? Through your stories and sightings, I’d like to map their exploits.

Swimming Eagles

Did you know bald eagles can swim?

Several locals have been lucky enough to see an eagle’s butterfly stroke in action.

“I saw two eagles diving on a duck,” said Bill Lloyd of Home. “Finally, one of them got it. It took it 20 minutes to swim that duck to shore.” He mimed the slow stroke of the eagle’s massive wet wings. “Twenty minutes later, it was on the shore. It gets up, squirrels around, gets that duck to where it can take off with it, and there it goes.”

His wife, Lynn Lloyd, said seagulls harassed it all the while. “Seagulls are like policemen in the bay.”

Karen McDonell of Burley Lagoon agreed. “We always hear because the crows or the seagulls make a hoopla. The birds tell us everything.”

“We saw an eagle swimming a fish into shore from just in front of our house. It was amazing," McDonell said.

The eagle used its wings like oars. A seal waited just offshore to see if it might get any scraps. The eagle hopped the fish onto the beach and ate it.

Local birders Faye McAdams Hands, Laurel Parshall, Melissa Sherwood, and Diane Yorgason-Quinn had a similar experience this winter. They were on a raptor survey near Oakville and had paused alongside the Chehalis River. A bald eagle dove into the river.

“The suddenness of the drop, pretty much vertical,” Parshall said. “And then breaking the surface with the power of her wing strokes.” The eagle set off swimming with a fish too big to lift.

“I was amazed at the distance she paddled,” Yorgason-Quinn said. “She showed no fatigue. The aura I felt from her was ‘determination.’ ”

The group spied a second eagle watching from a tree branch above. It was smaller. They presumed it to be the swimming eagle’s mate — female raptors are a third bigger than males.

The female eagle swam among the flooded river’s root wads and log jams. “It took a moment or two to realize where she was heading,” Parshall said. “She beelined her way to a more distant gravel bar.”

“It was like watching an Olympic swimmer going for gold in the breaststroke — if they swam while holding a struggling fish as heavy as they are with their toes.”

The eagle made it to the gravel bar and stood atop the large twisting fish. Then she took a killing bite from the salmon’s throat.

Shaggy Mouse Sea Slugs

Last month, Vaughn resident Justina Pritzker was exploring the low tide shallows of Taylor Bay Park with her daughter. They waded into a silty area where larger rocks were covered in aggregating anemones.

They noticed nudibranchs everywhere. There were dozens of the sea slugs. Pritzker’s daughter jumped onto her back, not wanting to step on them.

What a find: They had stumbled upon a mating group of the shaggy mouse nudibranch.

“They are one of my favorite animals to talk about because they are so unbelievably weird,” said Rachel Easton of Harbor WildWatch.

“They eat anemones and can somehow take the unfired cnidocytes (stingy cells) and pass them through their body undigested and put them on their backs to use for their own defense. It’s like eating a bowl of bees, not getting stung, and then putting their stingers on your fingers.”

Another name for this anemone eater? Shag rug sea slug. A rhyming double-spondee — what a name — and an apt description of the pile of gently waving flaps that protrude from its back.

Nudibranchs have no hard parts and are some of the most colorful creatures in the sea. There are over 3,000 species worldwide.

In our area, shaggy mouse nudibranchs like aggregating anemones best. These are the densely packed, small anemones that cover low-tide boulders. When exposed to air, the anemones look like slimy blobs. Underwater, they unfurl green-and-pink tentacles. It is the tentacles the nudibranchs like to eat.

Aggregating anemones have the ability to clone themselves by splitting in half. If you look at one of those anemone-covered boulders, look for a narrow line of bare rock between the aggregations. This is the boundary between two clones.

When a nudibranch approaches with special mucus to repel the anemone’s stings, an anemone retracts its tentacles and column. Then it bulges its column and releases an alarm pheromone called anthopleurine. If the nudibranch persists, the anemone can crawl on its column to escape. If that fails, the anemone releases its hold and lets the water take it where it will.

A shaggy mouse nudibranch takes not only stinging cells from its anemone meals but anthopleurine as well. A week after a meal, its approach, leaking pheromones, can cause anemones to react defensively before they are touched. The nudibranch also picks up two types of photosynthetic algae that live symbiotically in aggregating anemone tissues. These algae move into the nudibranch’s body unharmed and continue to photosynthesize. It is unknown if and how the nudibranch benefits.

I guess both nudibranchs and eagles, when they swim by using their wings as fins, know that as predators, sometimes you must become your prey.